加州一種野花揭示了新近記錄的進化過程 (2/2)

Recently the CNN.com reported the following:

A wildflower in California reveals a newly documented evolutionary process (2/2)

CNN = By Jacopo Prisco

UPDATED MAR 12, 2026

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To understand the process, the researchers kept track of wildflower populations across 19 sites, which were visited every year to assess whether the plants lived or died. They then collected seeds from the plants, grew them in a lab, and then ground up the leaves from the plants they’d grown to extract DNA.

The DNA was then used to sequence the plant’s genome — its genetic instructions. “We were able to see this rapid evolution happen within seven years,” Anstett said, adding that the genetic mutations that the plant leveraged to become drought resistant weren’t new, but probably developed a long time ago. The plants that carried these drought-resistant traits were able to survive and pass those mutations forward via the seeds.

The next step in the study, which Anstett says could eventually span 30 or 40 years, is to see whether these mutations that allowed the plants to survive the megadrought will continue to be beneficial or hinder the plants if the drought stops.

More evidence of evolutionary rescue does not make drought or climate change less concerning, but it suggests that there could be more plants or animals that might be able to show resilience under extreme duress. Key for that to happen is genetic diversity, which means that conservation efforts to keep plant populations as widespread as possible are still crucial.

“The amount of genetic variation can be critical to this adaptation,” said Anstett. “This is a hint to conservation biologists to try to improve the amount of genetic variation and the connectivity between habitats so that organisms are able to ultimately be more resilient to a range of stressors.”

‘A real breakthrough’

Demonstrating that evolutionary rescue happens in the wild and identifying the specific genes responsible has been a major outstanding goal in evolutionary and conservation biology, David Field, an associate professor of applied biosciences at Macquarie University in Australia, said in an email. Field was not involved with the new study.

“The researchers used an elegant experiment to demonstrate that evolutionary rescue actually happens in the wild in our lifetime,” he wrote in an email, adding that the study provides an important demonstration of the possibilities of using similar experiments to help conservation efforts of endangered species globally.

Other researchers who also did not participate in the research expressed similarly positive views: “This is a very important study,” Diane Campbell, distinguished professor emerita of ecology & evolutionary biology at the University of California, Irvine, said in an email. “It provides exceptionally strong evidence that a process known mostly from theory can help wild plant populations recover from the increasing droughts predicted under climate change in Mediterranean-type areas.”

A major question on the mind of botanists is whether plants can evolve in time to survive the extreme droughts that are predicted to get worse with climate change, said Isaac Lichter Marck, a botanical researcher at the California Academy of Sciences. “When faced with extreme drought, animals can move, adapt, or die — but wildflowers are rooted in place, leaving them with a much shorter list: adapt or die,” he wrote in an email.

The study is a critical model for using genomics to predict which wildflower species are vulnerable to extinction as a result of climate change, he continued. But it also raises other concerns: “Pressures like habitat loss and invasive species are eroding genetic variation in the wild. As this research shows, loss of genetic variation could make the already alarming threats from climate change even worse.”

Jeff Diez, an associate professor in the biology department of the University of Oregon, said in an email that the research represents a real breakthrough and stands out for its sheer thoroughness. “The sobering part is that it took an extraordinary effort to show this for one species,” he added. “If we want to understand how whole communities of interacting species will respond to climate change, we need to assess evolutionary potential across far more species, and there is bound to be enormous variation in which species can evolve fast enough.”

Overall, he concluded, the study contains the genuinely hopeful message that some wild plants may evolve fast enough to survive climate disruption. “But it’s also wrapped in a humbling reminder of how much we still don’t know.”

Translation

加州一種野花揭示了新近記錄的進化過程 (2/2)

（繼續）

為了了解這個過程，研究人員追蹤 19 個地點的野花族群，每年都會前往這些地點評估植物的存活情況。隨後，他們收集了植物的種子，在實驗室中培育，並將培育出的植物葉片研磨成粉末提取 DNA。

研究人員之後利用這些 DNA 對植物的基因組（即其遺傳指令）進行定序。 Anstett 說: “我們能夠在七年內觀察到這種快速進化” 。他還補充道，該植物利用的抗旱基因突變並非新的，可能在很久以前就已經產生。攜帶這些抗旱性狀的植物可以存活，並透過種子將這些突變傳遞給後代。

研究的下一步，Anstett表示最終可能會持續30或40年，就是要觀察這些使植物在超級乾旱中存活下來的突變，在乾旱停止後是否會繼續有益，還是會阻礙植物生長。

更多進化拯救的證據並不能減輕乾旱或氣候變遷帶來的擔憂，但它表明，世上可能存在更多能夠在極端困境下展現韌性的動植物。而實現這一點的關鍵在於遺傳多樣性，這意味著盡可能保持植物族群分佈廣泛的保育工作仍然至關重要。

 Anstett說: 「遺傳變異的數量對於這種適應至關重要」; 「這提示保育生物學家應該努力提高遺傳變異的數量和棲息地之間的連通性，從而使生物體最終能夠更好地應對各種壓力」。

“一個真正的突破”

澳洲麥考瑞大學應用生物科學副教授David Field在一封電子郵件中表示，這證明進化拯救現像在自然界中確實存在，而去識別出負責的特定基因，一直是進化生物學和保育生物學領域一個重大的未解目標。Field並未參與這項新研究。

他在電子郵件中寫道：「研究人員運用了一項精妙的實驗，證明了進化拯救現像在我們有生之年確實會在自然界中發生」。他還補充說，這項研究有力地證明了利用類似實驗在全球範圍內幫助瀕危物種保護工作的可能性。

其他未參與這項研究的研究人員也表達了類似的正面看法。加州大學歐文分校生態與演化生物學榮譽退休教授Diane Campbell在一封電子郵件中寫道：「這是一項非常重要的研究」; 「這項研究提供了極其有力的證據，表明一種主要存在於理論中的過程，是可以幫助野生植物種群，從氣候變遷預測到的地中海型地區的日益嚴重的干旱中恢復過來」。

加州科學院的植物研究員Isaac Lichter Marck表示，植物學家關注的一個主要問題是，植物能否及時進化以應對氣候變遷預計到會加劇的極端乾旱。他在一封電子郵件中寫道: 「面對極端乾旱，動物可以選擇遷徙、適應或死亡 - 但野花紮根於此，它們的生存選擇就少得多：要么適應，要么死亡」。

他繼續說道，這項研究為利用基因組學去預測哪些野花物種容易因氣候變遷而滅絕提供了一個重要的模型。但這項研究也引發了其他擔憂：“棲息地喪失和外來物種入侵等壓力正在侵蝕野生植物的遺傳多樣性。正如這項研究表明的那樣，遺傳多樣性的喪失可能會使氣候變遷帶來的本已令人擔憂的威脅雪上加霜。”

俄勒岡大學生物系副教授Jeff Diez在電子郵件中表示，這項研究是一項真正的突破，其嚴謹且細緻程度令人矚目。 他補充道:「令人深思的是，僅僅針對一個物種就需要付出巨大的努力」; 「如果我們想了解整個相互作用的物種群落將如何應對氣候變化時，我們需要評估更多物種的進化潛力，而它們中那種是有足夠進化速度潛力必然存在巨大差異」。

他總結道，總的來說，這項研究傳遞了一個真正令人鼓舞的訊息：一些野生植物或許能夠進化到足以應對氣候變遷的速度。 “但它同時也包裹著一個令人謙卑的提醒，我們仍然有很多未知的領域。”

              So, in California some populations of wildflowers have defied the odds to survive an ordeal. Researchers say they now believe these flowers relied on a type of rapid genetic evolution to do this. This study provides an important demonstration of the possibilities of using similar experiments to help conservation efforts of endangered species globally. The challenging part is that it may take much effort to show this for just one species. Apparently, if we want to understand how the whole communities of interacting species will respond to climate change, we need to assess evolutionary potential across far more species, and that commands a lot of research work. The findings of this research reminder us how much we still don’t know.